In the United States, we are in the process of seeing the baby boomers — the most productive, highly skilled, educated part of our labor force — retire. They are being replaced by groups of young workers who have regrettably scored rather poorly in international educational match-ups over the last two decades”

Most disturbing is that the average income of U.S. households headed by 25-year-olds and younger has been declining relative to the average income of the baby boomer population. This is a reasonably good indication that the productivity of the younger part of our workforce is declining relative to the level of productivity achieved by the retiring baby boomers. This raises some major concerns about the productive skills of our future U.S. labor force.

Most high-income people in our country do not realize that their incomes are being subsidized by their protection from competition from highly skilled people who are prevented from immigrating to the United States. But we need such skills in order to staff our productive economy, so that the standard of living for Americans as a whole can grow. [...]

My view is that we should give a green card to every immigrant who gets an advanced degree in the United States. The proportion of those people who will be terrorists is miniscule. That would have a major positive economic impact.

私は米国で学士号より上の学位を取った移民には全員グリーンカードをくれてやるべきだと思う。そのうちテロリストになる人の率なんてたかが知れてるし、これは経済に大きなプラスの影響をもたらすはずだ。- Alan Greenspan, former chairman of U.S. Federal Reserve; The Globalist

You cannot simply put entry-level and senior-level incomes in comparison. He's probably right in arguing that US needs more international competition in labor force. But then I wonder why There Are 5,000 Janitors in the U.S. with PhDs. The reality might be... Gen-X and Y got so efficient that employers don't hire as much as before.